High-wettability battery structure

Abstract

The invention provides a high-wettability battery structure, and relates to the technical field of batteries, a top cover structure comprises a cover plate and lower plastic mounted below the cover plate, and a positioning structure is arranged between the cover plate and the lower plastic; a supporting plate piece is fixed in the shell, the middle of the supporting plate piece is hollow, a plurality of bosses are arranged at the top of the supporting plate piece, and the outer area of the naked battery cell is smaller than the area of the hollow position of the supporting plate piece; the cover plate and the lower plastic cement are provided with corresponding liquid injection holes and openings, a liquid channel is arranged in the lower plastic cement, the edge of the lower plastic cement is provided with a plurality of overflow grooves, the liquid channel extends to each overflow groove, and a plurality of through-hole-shaped micropores are distributed in the bottom wall of the liquid channel, so that the electrolyte is transmitted into the naked battery cell in a large range in a small impact force manner; the wettability of the electrolyte on a pole piece coating is improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically, to a battery structure with high wettability. Background Technology

[0002] With the development of energy storage and power battery fields, once the energy density of a single battery cell exceeds a critical value, the complexity of its internal physicochemical processes increases exponentially. Among these, the wetting efficiency of the electrolyte in the high-voltage solid electrode has become a key bottleneck restricting the performance release and long-cycle stability of ultra-large capacity battery cells.

[0003] Specifically, the rapid increase in cell size leads to increased electrode thickness and significantly improved porosity, resulting in a geometrically extended permeation path for the electrolyte in the microporous structure.

[0004] Currently, before electrolyte injection in prismatic battery cell manufacturing, a cover plate is welded to the prismatic shell. The welding position between the two is a ring, which cannot guarantee that the cover plate completely covers the prismatic shell, leading to poor welding and inadequate sealing, resulting in leakage later. When the electrolyte wets the electrode sheets, the traditional method relies on a passive wetting mechanism of capillary action. This mechanism has a drastic performance degradation in large-scale electrode sheets. Most existing prismatic battery cells are made by preparing bare cells using large-scale electrode sheets. Electrolyte is injected through the injection hole, and the electrolyte flows into the prismatic shell and wets the electrode sheets as the electrolyte level rises. When the electrolyte enters the prismatic battery, it flows to a single position in the bare cell. If the electrolyte flow rate is too fast, it can easily impact and peel off the electrode coating and affect the uniformity of electrolyte wetting in the bare cell. The traditional injection structure can no longer meet the requirements of high wetting, affecting the battery's performance release and long cycle life. Therefore, there is an urgent need for a new battery structure with high wetting performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that when the electrolyte enters the prismatic battery, it flows to one position of the bare cell. The electrolyte flow rate is too fast and it is easy to knock off the electrode coating. It also affects the uniformity of electrolyte wetting of the bare cell. In view of the problems existing in the prior art, a battery structure with high wettability is provided.

[0006] The purpose and effects of this invention are achieved by the following specific technical means: a highly wettable battery structure, including a housing, a top cover structure installed on the top of the housing, and a bare battery cell installed at the bottom of the top cover structure; The top cover structure includes a cover plate and a lower plastic piece installed below the cover plate, and a positioning structure is provided between the cover plate and the lower plastic piece; A support plate is fixed inside the housing. The support plate has a hollow center and several protrusions on its top. The outer area of ​​the bare battery cell is smaller than the area of ​​the hollow part of the support plate. The cover plate and the lower plastic have corresponding injection holes and openings, and the lower plastic has a liquid channel inside. The lower plastic has several overflow grooves on its edge, and the liquid channel extends to each overflow groove. The bottom wall of the liquid channel has several through-hole-shaped micropores. The overflow groove has a block inside, and the boss corresponds to each overflow groove. The boss is squeezed and deformed by the block to open the overflow groove, and the opening position of the overflow groove is located within the hollow position of the support plate.

[0007] A further preferred embodiment: a positive terminal and a negative terminal are respectively installed on the left and right sides of the cover plate, and an explosion-proof valve is provided on the top of the cover plate between the positive terminal and the negative terminal; The lower plastic part has electrode holes corresponding to the positive and negative electrode positions, and the positive and negative electrode positions pass through the electrode holes to be electrically connected to the bare battery cell. The lower plastic part has a mesh pressure reducing part corresponding to the explosion-proof valve position.

[0008] A further preferred embodiment: the positioning structure includes a connecting part and a connecting groove, the connecting part and the connecting groove are respectively disposed at the liquid injection hole and the opening connection position, and the connecting part and the connecting groove are correspondingly connected.

[0009] A further preferred embodiment: an inner baffle is provided at the bottom end of the inner wall of the opening, and the inner baffle is made of rubber. The inner wall of the injection hole is provided with a cylindrical insert, which penetrates into the opening, and the bottom of the insert abuts against the inner baffle to make it unfold downward.

[0010] A further preferred embodiment: the inner baffle has a groove on the side facing the plug, and the end of the plug is slidably connected to the groove. After the cover plate and the lower plastic are installed, the plug is located at the end of the groove.

[0011] A further preferred embodiment: a sealing groove is provided outside the injection hole, and the injection hole and the sealing groove form a T-shape.

[0012] A further preferred embodiment: the area of ​​the lower plastic part is slightly larger than the hollow space of the tray component, and the edge of the lower plastic part abuts against the tray component; The lower plastic part and the pallet part have an overlapping portion, and the width of the overlapping portion is ≥2mm.

[0013] A further preferred embodiment: the overflow channels are distributed at least on both sides of the lower plastic, and there are no less than three on each side. The overflow channels are L-shaped and open on both the Y-axis and X-axis directions of the outer corner of the lower plastic. A blocking component is fixed to the top of the overflow channel. The top of the boss is tightly connected to the inner wall of the overflow groove.

[0014] A further preferred embodiment: the liquid channel expands outward from the injection hole as the initial position and the height decreases from high to low.

[0015] A further preferred embodiment: the cover plate is welded to the shell, and in the welded state of the cover plate and the shell, the boss squeezes the block and connects to the overflow groove.

[0016] The beneficial effects of this invention are: 1. The bottom wall of the liquid channel has several through-hole-shaped micropores with a diameter of approximately 0.5 mm. The electrolyte slowly drips through the micropores into the bare cell, initially wetting the electrode sheet without impacting the electrode coating. Multiple overflow grooves start injecting electrolyte from the side of the bare cell, making it less likely to directly impact the electrode coating and solving the problem of coating slurry peeling. The electrolyte is transferred into the bare cell over a large area with low impact force, improving the wettability of the electrolyte to the electrode coating. 2. When the cover plate is connected to the housing, the boss abuts against the block and opens the overflow groove. This ensures an effective connection between the cover plate and the housing. If the connection between the cover plate and the housing is not in place, the boss cannot open the overflow groove. Therefore, during the subsequent liquid injection process, the liquid injection status can be observed to determine whether the boss is positioned in the overflow groove. If the liquid injection is poor, it proves that the connection between the cover plate and the housing is poor. Using this solution to manufacture and assemble the structural components of the square-shell type battery cell facilitates the timely detection of defective products and ensures product quality. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a bottom view of the cover plate structure of the present invention; Figure 3 This is a schematic diagram of the lower plastic structure of the present invention; Figure 4 This is a schematic diagram of the internal structure of the lower plastic part of the present invention; Figure 5 This is a front view of the injection hole and opening structure of the present invention (in disassembled state). Figure 6 This is a front view of the injection hole and opening structure of the present invention (installation state). Figure 7 For the present invention Figure 3 A magnified schematic diagram of the structure at point A in the diagram; Figure 8 For the present invention Figure 3 A magnified schematic diagram of the structure at point A in the diagram; Figure 9 This is a partial bottom view of the plastic structure of the present invention (location of the overflow groove); Figure 10 This is a partial bottom view of the plastic structure of the present invention (location of the overflow groove); Figure 11 This is a partial side view of the plastic structure of the present invention (location of the overflow groove).

[0019] Figures 1-11 In the middle: shell (1), support plate (101), boss (102), cover plate (2), injection hole (201), connecting part (3), plug (4), sealing groove (5), lower plastic (6), liquid channel (7), micro hole (701), overflow groove (8), blocking part (801), block (9), opening (10), connecting groove (1001), inner baffle (11). Detailed Implementation

[0020] To better understand the above-mentioned objects, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. On the contrary, any modifications and refinements made without departing from the scope of the present invention are within the scope of patent protection of the present invention.

[0021] Please see Figures 1-3 A highly wettable battery structure includes a housing 1, a top cover structure installed on the top of the housing 1, and a bare battery cell (not shown in the figure) installed at the bottom of the top cover structure. The top of the bare battery cell is provided with a positive electrode tab and a negative electrode tab respectively. A positive electrode post and a negative electrode post are installed on the left and right sides of the cover plate 2 respectively. The lower plastic 6 is provided with electrode post holes corresponding to the positions of the positive electrode post and the negative electrode post for the electrode post to pass through. The positive electrode post and the negative electrode post pass through the electrode post holes and are electrically connected to the electrode tabs of the bare battery cell. The top cover structure is then assembled with the bare battery cell. Preferably, an explosion-proof valve is provided at the top of the cover plate 2 between the positive and negative terminals, and a mesh pressure-reducing part is provided on the lower plastic 6 corresponding to the position of the explosion-proof valve. The mesh pressure-reducing part is sunken. When the battery explodes, the pressure concentration can be reduced by the mesh pressure-reducing part, and then the pressure is released by the explosion-proof valve.

[0022] Please see Figures 1-6 The top cover structure includes a cover plate 2 and a lower plastic 6 installed below the cover plate 2. The lower plastic 6 and the cover plate 2 are connected by ultrasonic heat fusion. The cover plate 2 and the lower plastic 6 have corresponding injection holes 201 and openings 10. A positioning structure is provided between the injection holes 201 and the openings 10. After the cover plate 2 is connected to the lower plastic 6, the injection holes 201 and the openings 10 are arranged vertically (e.g., Figure 5 and Figure 6The positioning structure includes a connecting part 3 and a connecting groove 1001. The connecting part 3 and the connecting groove 1001 are respectively provided at the connection position of the injection hole 201 and the opening 10. The connecting part 3 and the connecting groove 1001 are connected in a concave-convex manner. The connecting groove 1001 is concave and the connecting part 3 is convex. The two are connected to each other to achieve the effect of foolproof positioning. The depth of the connecting groove 1001 is ≥1mm. The length of the connecting part 3 in the Y-axis direction is equal to the depth of the connecting groove 1001, which can increase the connection area between the cover plate 2 and the lower plastic 6 and improve the connection. Preferably, a cylindrical insert 4 is provided on the inner wall of the injection hole 201. When the cover plate 2 is connected to the lower plastic 6, the insert 4 penetrates into the opening 10. An inner baffle 11 is provided at the bottom of the inner wall of the opening 10. The inner baffle 11 is made of rubber (e.g., ...). Figure 5 The inner baffle 11 has a groove on the side facing the insert 4. The end of the insert 4 enters the groove. As the insert 4 gradually penetrates into the opening 10, it pushes the inner baffle 11 downward and slides within the groove. After the cover plate 2 and the lower plastic 6 are installed, the inner baffle 11 unfolds downward. Figure 6 The plug 4 is located at the end of the groove. The end of the plug 4 and the corner of the end of the groove form a snap-fit, making them difficult to separate. This also serves as a positioning and connection function. The inner baffle 11 made of rubber has a large friction with the plug 4, which provides an anti-slip effect.

[0023] Please see Figures 1-3 After the cover plate 2 and the lower plastic 6 are connected, the bare battery cell can be placed into the housing 1. The housing 1 has a support plate 101 fixed inside. The support plate 101 has a hollowed-out center. The outer area of ​​the bare battery cell is smaller than the area of ​​the hollowed-out position of the support plate 101 so that the bare battery cell can pass through the hollowed-out position of the support plate 101 and enter the housing 1 smoothly. After the bare battery cell is placed into the housing 1, the area of ​​the lower plastic 6 is slightly larger than the hollowed-out space of the support plate 101. Therefore, after the lower plastic 6 moves down to a certain position, there will be an overlap between it and the support plate 101. The width of the overlap is ≥2mm. The edge of the lower plastic 6 will abut against the support plate 101, restricting the lower plastic 6 and the cover plate 2 from moving down. The cover plate 2 is then closed in the open position of the housing 1. The cover plate 2 and the support plate 101 are installed. Preferred, such as Figure 1 , Figure 4 , Figure 5 and Figures 7-11 The lower plastic 6 has a liquid channel 7 inside, which communicates with the opening 10. Several overflow grooves 8 are formed along the edge of the lower plastic 6, and the liquid channel 7 extends to each overflow groove 8. The top of the support plate 101 has several protrusions 102. A plug 9, made of rubber, is installed inside the overflow groove 8. The top of the plug 9 is preferably adhered to the inner wall of the overflow groove 8. This connection should not be loosened or detached. Initially, the plug 9 is sealed in the overflow groove 8. When the lower plastic 6 abuts against the support plate 101, the protrusions 102 will correspond to each plug 9 (e.g., ...). Figure 11The boss 102 does not completely cover the bottom surface of the block 9, leaving a width of about 0.4mm. When the cover plate 2 is welded to the housing 1, the cover plate 2 needs to be pressed down, and the boss 102 will be squeezed against the block 9 to deform it and open the overflow groove 8. The block 9 is blocked in the X-axis direction of the overflow groove 8, while the overflow groove 8 is opened at the bottom in the Y-axis direction. The opening position of the overflow groove 8 is located within the hollow position of the support plate 101. Similarly, the overflow groove 8 will be connected to the space for the bare cell installation inside the housing 1 at this time. Furthermore, only after the boss 102 aligns with the block 9 can the cover plate 2 be pressed down and approach the housing 1. If the cover plate 2 is installed backwards, the boss 102 will block the lower plastic 6 and the cover plate 2 cannot be pressed down. The boss 102 and the block 9 can form a positioning point to prevent fooling. After the cover plate 2 is fully pressed down, it will be parallel to the housing 1. The horizontal state of the cover plate 2 can be confirmed through multiple positioning points to avoid the cover plate 2 tilting and causing poor welding.

[0024] Please see Figures 3-6 and Figure 10 After the cover plate 2 is firmly welded to the shell 1, electrolyte is injected. The electrolyte enters the opening 10 through the injection hole 201. The inner baffle 11 is inclined in the liquid channel 7 (e.g., Figure 6 When the electrolyte enters the opening 10 through the injection hole 201, the inner baffle 11 reduces the flow rate of the injection hole 201. The electrolyte is transported within the liquid channel 7, which extends from the injection hole 201 to the overflow tank 8, with the height decreasing from high to low. Figure 10 The bottom of the liquid channel 7 is inclined, so the electrolyte will be transported to multiple different overflow tanks 8 (e.g., Figure 4 The bottom wall of the liquid channel 7 has several through-hole-shaped micropores 701, with a pore diameter of about 0.5 mm. The electrolyte slowly seeps through the micropores 701 and drips into the bare cell, initially wetting the electrode sheet without impacting the electrode sheet coating. The overflow grooves 8 are distributed at least on both sides of the lower plastic 6, preferably on both sides of the large end face of the lower plastic 6 in the Z-axis direction, and the number of overflow grooves 8 on each side is not less than three. The number of overflow grooves 8 is relatively large and uniform, and the distribution range of the liquid channel 7 is also wider. The electrolyte flows into the bare cell from multiple positions, covering a larger area. The liquid injection speed is faster than that of the traditional single liquid injection hole 201. Moreover, the multiple overflow grooves 8 start liquid injection from the side of the bare cell, which is not easy to directly impact the coating of the electrode sheet, solving the problem of coating slurry peeling. The electrolyte is transferred into the bare cell over a large area in a way with less impact force, improving the wettability of the electrolyte to the electrode sheet coating. While the cover plate 2 is connected to the housing 1, the boss 102 abuts against the block 9 and opens the overflow groove 8. This ensures an effective connection between the cover plate 2 and the housing 1. If the connection between the cover plate 2 and the housing 1 is not in place, the boss 102 cannot open the overflow groove 8. Therefore, during the subsequent liquid injection process, the liquid injection status can be observed to determine whether the boss 102 is positioned in the overflow groove 8. If the liquid injection is poor, it proves that the connection between the cover plate 2 and the housing 1 is poor. Using this solution to manufacture and assemble the various structural components of the square-shell type battery cell facilitates the timely detection of defective products and ensures product quality.

[0025] like Figure 5 As shown, in the initial state, the inner baffle 11 can block the opening 10 to prevent external dust and impurities from falling into the liquid channel 7 and contaminating the electrolyte.

[0026] like Figure 9 As shown, a blocking member 801 is fixed at the top of the overflow tank 8. The end of the blocking member 801 away from the overflow tank 8 is slightly tilted downward. The blocking member 801 blocks the top of the block 9, preventing the block 9 from being squeezed into the liquid channel 7 by the boss 102, and preventing the block 9 from falling out of the overflow tank 8.

[0027] like Figure 6 As shown, a sealing groove 5 is provided outside the injection hole 201. The injection hole 201 and the sealing groove 5 form a T-shape. This T-shape position facilitates the insertion of sealing nails after injection to seal the injection hole 201.

Claims

1. A highly wettable battery structure, comprising a housing, a top cover structure mounted on the top of the housing, and a bare battery cell mounted on the bottom of the top cover structure, characterized in that: The top cover structure includes a cover plate and a lower plastic piece installed below the cover plate, and a positioning structure is provided between the cover plate and the lower plastic piece; A support plate is fixed inside the housing. The support plate has a hollow center and several protrusions on its top. The outer area of ​​the bare battery cell is smaller than the area of ​​the hollow part of the support plate. The cover plate and the lower plastic have corresponding injection holes and openings. The lower plastic has a liquid channel inside and several overflow grooves on its edge. The liquid channel extends to each overflow groove. The bottom wall of the liquid channel has several through-hole-shaped micropores. A block is provided inside the overflow groove. The boss corresponds to each overflow groove. The boss is squeezed and deformed by the block to open the overflow groove. The opening position of the overflow groove is located within the hollow position of the support plate.

2. The battery structure with high wettability according to claim 1, characterized in that: Positive and negative terminals are installed on the left and right sides of the cover plate, respectively, and an explosion-proof valve is installed on the top of the cover plate between the positive and negative terminals. The lower plastic part has electrode holes corresponding to the positive and negative electrode positions. The positive and negative electrode positions pass through the electrode holes and are electrically connected to the bare battery cell. The lower plastic part has a mesh pressure reducing section corresponding to the explosion-proof valve position.

3. The battery structure with high wettability according to claim 1, characterized in that: The positioning structure includes a connecting part and a connecting groove, which are respectively disposed at the injection hole and the opening connection position, and the connecting part and the connecting groove are connected in a concave-convex manner.

4. The battery structure with high wettability according to claim 1, characterized in that: An inner baffle is provided at the bottom of the inner wall of the opening, and the inner baffle is made of rubber. The inner wall of the injection hole is provided with a cylindrical insert, which penetrates into the opening, and the bottom of the insert abuts against the inner baffle to make it unfold downward.

5. A battery structure with high wettability according to claim 4, characterized in that: The inner baffle has a groove on the side facing the plug, and the end of the plug is slidably connected to the groove. After the cover plate and the lower plastic are installed, the plug is located at the end of the groove.

6. The battery structure with high wettability according to claim 1, characterized in that: The injection hole is provided with a sealing groove, and the injection hole and the sealing groove form a T-shape.

7. A battery structure with high wettability according to claim 1, characterized in that: The lower plastic area is slightly larger than the hollow space of the tray component, and the edge of the lower plastic abuts against the tray component; The lower plastic part and the pallet part have an overlapping portion, and the width of the overlapping portion is ≥2mm.

8. A battery structure with high wettability according to claim 1, characterized in that: The overflow channels are distributed on at least both sides of the lower plastic, with no less than three on each side. The overflow channels are L-shaped and open on the outer corners of the lower plastic in two directions: the Y-axis and the X-axis. A blocking component is fixed to the top of the overflow channels. The top of the boss is tightly connected to the inner wall of the overflow groove.

9. A battery structure with high wettability according to claim 1, characterized in that: The liquid channel expands outward from the injection hole as the initial position, and its height decreases from high to low.

10. A battery structure with high wettability according to claim 1, characterized in that: The cover plate is welded to the shell, and in the welded state of the cover plate and the shell, the boss squeezes the block and connects to the overflow groove.

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